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What You Need to Know About Intestinal Gas

Posted Aug 24 2008 1:49pm

DAVID MARKS, MD: Hi, and welcome to our webcast. I'm Dr. David Marks. Today we're talking about gas. While it's often very embarrassing, it's a common complaint in doctors' offices. What exactly causes gas? And what can you do to get over the discomfort of gas?

Joining us today are two experts. First is Dr. Lucy Harris. She's a gastroenterologist at Cornell Medical Center. Thanks for being here.

LUCINDA HARRIS, MS, MD: Thank you.

DAVID MARKS, MD: Next to her is Dr. Mark Pochapin. He's also a gastroenterologist, and also from the same institution, Cornell Medical Center. Thanks for being here.

MARK POCHAPIN, MD: Thanks.

DAVID MARKS, MD: What's normal? What is the normal amount of gas? Everybody has it.

LUCINDA HARRIS, MS, MD: They actually have studied gas, and they studied gas originally in young, healthy males, and found that young healthy males pass gas 8-20 times day, about two to four pints of gas per day. They've actually never done these studies in women, but that's sort of been the basis of our consideration of what's normal for gas.

DAVID MARKS, MD: Why does gas occur in the first place?

MARK POCHAPIN, MD: Gas can really get into the intestine in two main ways. One, it's swallowed, and it just doesn't leave the intestine. People, after they eat a meal, may belch, and the gas can escape through the mouth. Or food itself is actually fermented by bacteria, or malabsorbed, and some of the products of malabsorption are then utilized by bacteria in the intestine, mainly in the colon, and the bacteria look at that as food to produce a lot of byproducts, and some of the byproducts are gas.

DAVID MARKS, MD: Does that mean that belching is normal?

LUCINDA HARRIS, MS, MD: Belching, to some extent, is normal phenomenon, but if someone is doing it all the time, it may be another symptom of gastroesophageal reflux disease or GERD as we sometimes call it, which is a more severe form of heartburn or indigestion.

MARK POCHAPIN, MD: Some people actually swallow more air in. In fact, some people, as a result of stress, will swallow quite a bit of air, the swallowing being something, like grinding your teeth, some people actually swallow more air when they eat, and swallow air during the day, and that might cause more bloating with gas, and belching.

LUCINDA HARRIS, MS, MD: People who smoke swallow more air.

DAVID MARKS, MD: Because they're inhaling.

LUCINDA HARRIS, MS, MD: Right. And people who chew gum also frequently do the same thing.

DAVID MARKS, MD: How does someone know when this is becoming a problem? Is it somebody else telling them that they're belching too much, or do they get symptoms of GERD?

LUCINDA HARRIS, MS, MD: They may get other symptoms of GERD, such as nausea, chest burning kind of chest pain, that occurs very frequently. But also just very frequent belching. If that's really happening a lot, then they really should talk to their doctor about it.

DAVID MARKS, MD: So if it interrupts their lifestyle or it impinges on whatever they're doing.

LUCINDA HARRIS, MS, MD: Mm-hm.

DAVID MARKS, MD: There are some dietary causes. What are the common ones?

MARK POCHAPIN, MD: I think one of the most common causes of gas is food that doesn't get absorbed well. And it may be a natural phenomenon or an unnatural phenomenon. A natural type of process would be artificial sweeteners. For example, something called sorbitol, which is put in a lot of gums, sugar-free gums. People who chew that may have a little more sensitivity. The sorbitol doesn't get absorbed. Again, the bacteria utilize it, and produce a lot of gas.

Unnatural, meaning not necessarily a disease per se would be milk sugar. Milk sugar, lactose, is really a baby food. The only reason we see it in our adult life is because we have domesticated animals. But the body isn't necessarily engineered to digest milk sugar. So if people have more of an enzyme problem digesting that, then actually that will be malabsorbed too. And, again, the bacteria will work on it and produce more gas.

There are certain fruits and vegetables, especially when they're raw, like cauliflower and broccoli that, again, we don't have the right enzymes to digest it completely, so a lot of the byproducts will then be utilized by bacteria to make, once again, more gas.

DAVID MARKS, MD: But cooking helps?

MARK POCHAPIN, MD: Yes, actually, if you break down some of the complex carbohydrates and sugars to something that we can better digest and absorb, you'll have less gas.

LUCINDA HARRIS, MS, MD: Another thing that people should realize is that we tend to think of lactose as dairy products, as just pure milk or ice cream, but actually it can have hidden forms in processed foods such as casein and whey. So people really do need to read labels as well.

DAVID MARKS, MD: I'm interested to know if this is going to be a bigger problem. There's a big push to get people drinking milk for calcium. Are we going to be seeing a lot more complaints in doctor's offices of GERD-like symptoms or too much gas production?

MARK POCHAPIN, MD: I think we're already seeing it. Milk is very healthy, especially, as adults we don't need the fat in milk. So skim milk or low-fat milk is a very healthy food. The problem is not the fat. People think: Oh, I may have a problem with lactose; I'll get skim milk. Has nothing to do with the fat, since skim milk is just fat-free milk. What it is is the sugar. So, yes, definitely.

And also, so many delicious desserts are used with very rich, creamy products that have a lot of lactose in it. And we see it. There's actually some easy testing that can be done. One way would just be to avoid all dairy altogether for a few days and see if the symptoms change. Another is a breath test, not invasive at all, which could measure the amount of hydrogen you produce in the challenge of a dairy or lactose load.

LUCINDA HARRIS, MS, MD: And LactAid milks and LactAid supplements are very easily available over-the-counter in the drugstore. The pills that you open up and sprinkle on foods. In addition, the LactAid milks are available.

One thing that people should be aware of is, I believe that there is now a milk that has 99 percent of the lactose absorbed if it's not digested. If it's not that product, the regular LactAid milk only has 70 percent of the lactose digested. So people with severe lactose intolerance may still get symptoms. The majority of us with mild lactose intolerance can probably tolerate a glass of milk a day.

DAVID MARKS, MD: But, as you said, it's in a lot of other foods that we eat. So they have to be careful with cheeses and everything else.

LUCINDA HARRIS, MS, MD: And there are lots of new calcium supplements. People can take Tums. There are these little candy squares called Viactiv; they're high in calcium.

MARK POCHAPIN, MD: And all women really should be taking, actually everybody should, but especially women, who are more prone to osteoporosis, should be taking some form of calcium supplement, especially as they get closer to menopause. Milk isn't the only source of calcium. Again, it's a good food. It has calcium and protein in it, but if you can't drink milk, you could certainly supplement the nutrients and the minerals.

LUCINDA HARRIS, MS, MD: I also think it's important for women to know that calcium carbonate and calcium citrate are more bioavailable forms of calcium, and also easier digested. If you don't get the calcium in those forms, you may get more constipation and bloating from the calcium supplements.

DAVID MARKS, MD: Let's talk about treatment of gas. There are a number of treatments available. How should a person start?

MARK POCHAPIN, MD: I think the most important thing is to try and figure out what's causing the gas in the first place. Because I don't think there are any really good treatments of gas. You go to the pharmacy and you get these gas pills. Virtually, they don't work.

LUCINDA HARRIS, MS, MD: They work on upper gas. They don't work on lower gas, the flatulence that people really complain about.

MARK POCHAPIN, MD: Which is usually the type of gas you hear most commonly, especially in a gastroenterologist's office.

DAVID MARKS, MD: Are you talking about, like, Simethicone and products like that?

LUCINDA HARRIS, MS, MD: Yes. Phazyme and Gas-X.

DAVID MARKS, MD: Gas-X. Those don't work for the majority of --

LUCINDA HARRIS, MS, MD: They work for the belching kind of gas. They don't work for the flatulence kind of gas.

MARK POCHAPIN, MD: Because they don't get rid of the gas. All they do is, they just break it up so you don't have the bubbles as much. Like you see the commercials, and you see the bubbles disappear. But the gas is still there.

LUCINDA HARRIS, MS, MD: Right. And there are charcoal tablets that they advertise for lower gas, but they often are constipating, and they turn the stool black, which is a little bit frightening for people. For that reason, I don't recommend them strongly.

MARK POCHAPIN, MD: Getting back to your question, what should you do, what treatment, is really trying to figure out what's causing it. So is there a certain food group that's causing it? Sometimes keeping a diary of when patients feel most bloated and gassy, when they're belching the most, and then trying to go back and see what they ate, and see if there's any similarity in the diet and in the diary that can help us figure out. So maybe just removing a food substance might be the best treatment, or cooking the vegetables really well.

LUCINDA HARRIS, MS, MD: And beans can be soaked. Beans, we know, are a big cause of gas, but they can be soaked and then cause less gas.

DAVID MARKS, MD: Soaked in what?

LUCINDA HARRIS, MS, MD: In water, actually. Then we also know that there are, if you have sort of more frequent, smaller amounts of the cruciferous vegetables, you'll probably have less symptoms.

MARK POCHAPIN, MD: And minimizing chewing gum, carbonated beverages. You're drinking bubbles in the carbonated beverages. There was a patient of mine who came into my office, and she doesn't understand why she has all this gas. And she pulls out of her purse this big thing of bottled mineral water that's carbonated, and she says she goes through six or seven of these bottles a day. That was it. That was the problem.

DAVID MARKS, MD: And, of course, another reason not to smoke. Amongst everything else.

MARK POCHAPIN, MD: That and a million other.

LUCINDA HARRIS, MS, MD: Absolutely.

DAVID MARKS, MD: Okay. Thank you both for being here. Thank you for watching our webcast. I'm Dr. David Marks, and I'll see you next time.